This invention relates to a reaction test for humans, and particularly to a screen based reaction test, the results of which may be useful in subsequent assessment diagnosis of the human condition.
Tests which measure the speed of reaction of a human to sudden change are well known. Generally speaking such tests categorize humans as fast and slow, the threshold between these categories being indicative of an ability to be suitable for a given task. For example humans selected for dangerous jobs might be required to show a rapid reaction to a sudden change.
Typically such prior art tests may consist of a lamp switching on or off, the reaction time being determined electronically by measuring the delay between the change of state of the lamp and the activation of a switch by the subject of the test. Security forces may use a pop-up target which appears for a limited time, and during which the subject must react, for example by aiming and firing a weapon.
Such tests provide a crude and simple means of placing humans into one of two groups, and the threshold can be varied with relative ease to select individuals with preferred reaction time.
The present invention provides a screen based reaction test adapted to give more detailed information concerning reaction times, and which may be useful in the subsequent assessment, diagnosis, treatment and/or therapy of an individual.
According to a first aspect of the invention there is provided apparatus for providing a test for humans, the apparatus comprising a device which provides a visual shape which is perceived to be moving along a path at varying speed by the human undergoing the test, the apparatus being arranged to vary the visual shape at a plurality of points along the path, and signalling means to be operated by the human undergoing the test as each change of shape is perceived.
Such a test requires a number of human inputs corresponding to each change of shape and permits a series of reaction times to be determined. each reaction time being the delay between a change of shape and the operation of the signalling means.
The speed of the visual shape along said path preferably increases as it progresses.
Preferably, the device which provides the visual shape comprises a screen on which the shape is displayed. The visual shape preferably moves across the screen along said path.
The signalling means may be in the form of a switch.
The device may be in the form of a computer and monitor, the computer being arranged to produce the visual shape and the monitor providing a screen across which the shape tracks to follow the path. In such a case, the signalling means may comprise a mouse, key board or joystick associated with the computer. The computer preferably receives signals from the mouse for processing to determine reaction times for the human undergoing the test. Data resulting from the test can be held in a memory of the computer for future analysis.
In the preferred embodiment, the shape may change from one predetermined shape to another, for example from a circle to a square, and back again. Animal shapes such as duck, mouse or rabbit may be more attractive to children, and adapted to ensure good compliance with the test protocol. The shapes preferably have approximately equal perception to an average human in a certain age category and the size of one shape may be adjusted relative to the size of another in order to achieve approximately equal perception.
In a preferred embodiment. the device is arranged to produce a visual shape in the form of a circular spot of 5 mm diameter. In that embodiment the square may have a side length of 5 mm.
The device may be arranged to operatic to provide a test of around 90 seconds duration during which time the shape may undergo at least 15 changes arid preferable more than 20 changes. 21 changes of shape are preferred.
The device may be arranged to provide a random duration between each change of shape. Alternatively, a predefined sequence of different time periods between shape changes may be selected.
The device is preferably arranged to increase the speed of movement of the shape along the path continuously through the test, typically from a starting speed of about 10 mm/sec to a finishing speed of about 200 mm/sec. The speed of movement may increase linearly, exponentially or in any other desired manner.
The size and speed of the shape may be related to screen size of a computer monitor. For example a screen size may be defined in terms of pixels (e.g. 664xc3x97338 pixels); a shape may be defined in pixels (e.g. a square having a side length of 12 pixels), and speed may be defined as pixels per second (e.g. a slow speed of 20 pixels per second to a fact speed of 800 pixels per second).
This latter arrangement may be more suitable where monitors of different size are used to perform the test, or where the test is driven remotely by a host computer.
According to another aspect of the invention there is provided a method of testing the reaction time of a human being to a visual stimulus, the method comprising the steps of providing a visual shape which the human undergoing the test will perceive to be moving alone a path at varying speed, varying the visual shape at a plurality of points along the path, and providing signalling means for operation by the human throughout the test as each change of shape is perceived.
The operation of the signalling means enables the delay between a change of shape and the operation of the signalling means to be determined for subsequent analysis. The method also permits slow or false operation of tie signalling means to be identified according to time thresholds. For example reaction time is classified as normal if within a first time period, slow if within a second time period greater than tile first period, and false if within a third time period greater than the second time period. The third time period ends at the next change of shape; that is to say the time periods are reset from catch change of shape. The first time period may be less that 50 ms, the second time period may be 50.100 ms, and the third time period may be more than 100 ms.
The method may include the step of requiring the human undergoing the test to perform the test at least twice and determining the time delays for the second or subsequent test only.
In the preferred embodiment a screen based reaction test for humans is provided for use with a monitor and switch, the test consisting of an artefact moving across a screen of the monitor for a predetermined period, the speed of movement of the artefact increasing from the beginning of the test to the end, and the artefact undergoing a plurality of changes of shape between the beginning and end of the test, a human operating said switch as each change of shape is perceived.
Such a test stimulates the required multiple human inputs corresponding to each change of shape, and permits a series of reaction times to be determined electronically, each reaction time being the delay between a change of shape of artefact and operation of the switch.
In the preferred embodiment the shape of the artefact alternates between two predefined shapes, for example a circle and a square. The shapes of artefact chosen preferably have approximately equal perception to an average human, and tile size of one artefact may be adjusted relative to the size of another artefact in order to achieve approximately equal perception.
According to a third aspect of the invention there is provided a computer, monitor and mouse in combination, the computer being caused to create an artefact moving across the screen of the monitor for a predetermined period, the artifact changing shape at intervals of not less than 1 second and not more than 10 seconds and the artefact increasing speed from the beginning of the test to the end of the test, and the computer having a memory to record the time of each change of shape of the artefact, and the time of a next subsequent input from said mouse, said times and corresponding inputs being stored in said memory for future analysis.
According to a fourth aspect of the invention there is provided an Internet site adapted to download a test correspondent, to the aforesaid method of testing the reaction time of a human being to a visual stimulus, the Internet site being adapted to receive and temporarily store the address of a human performing the test, to receive and temporarily store the results of the test and to e-mail the stored information to an operator of the Internet site.
According to a fifth aspect of the invention there is provided a computer program for providing a screen based reaction test for a personal computer and having the characteristics of the method aforesaid.